Effect of bed elevation discordance in the main river on the confluence hydrodynamics in 90o straight-channels’ confluences
Authors
Đorđević, Dejana
Contributors
Schleiss, Anton J.de Cesare, Giovanni
Franca, Mario J.
Pfister, Michael
Conference object (Published version)

Taylor & Francis Group
Metadata
Show full item recordAbstract
A role of the difference in bed elevations in the main-river (ΔzMR) at its entrance to a 90º straight-channels' confluence is studied numerically using a 3D finite-volume model. Three characteristic hydrological scenarios with DR = {0.250, 0.583, 0.750} are analysed in four confluence layouts having ΔzMR / hd [0.0, 0.50] (where hd stands for the flow depth in the deeper canal at the confluence). It is found that: 1) a portion of the tribu-tary flow in the bottom layers is entrained by the bed-step, 2) the w- velocity has the same order of magnitude as Vxy for ΔzMR ≥ 0.25hd and DR > 0.5, 3) the opposite bank is endangered by erosion due to strong upward motion along this bank, 4) additional shear layer develops on the outer side of the distorted umax-core and 5) the presence of bed-step favours bed-load transport both in and far downstream of the confluence.
Keywords:
river confluence / bed elevation discordance in the main river / flow angles δ and φ / size of the recirculation zone / shear layer / bed shear stress distributionSource:
River Flow 2014, Proceedings of the International Conference on Fluvial Hydraulics, Lausanne, Switzerland, 3-5 September 2014, 2014, 997-1005Publisher:
- CRC Press, Taylor & Francis Group
Funding / projects:
- Monitoring and Modeling of Rivers and Reservoirs (MORE) - Physical, Chemical, Biological and Morphodynamic Parameters (RS-37009)
- Urban Drainage Systems as Key Infrastructure in Cities and Towns (RS-37010)
Institution/Community
GraFarTY - CONF AU - Đorđević, Dejana PY - 2014 UR - https://grafar.grf.bg.ac.rs/handle/123456789/1858 AB - A role of the difference in bed elevations in the main-river (ΔzMR) at its entrance to a 90º straight-channels' confluence is studied numerically using a 3D finite-volume model. Three characteristic hydrological scenarios with DR = {0.250, 0.583, 0.750} are analysed in four confluence layouts having ΔzMR / hd [0.0, 0.50] (where hd stands for the flow depth in the deeper canal at the confluence). It is found that: 1) a portion of the tribu-tary flow in the bottom layers is entrained by the bed-step, 2) the w- velocity has the same order of magnitude as Vxy for ΔzMR ≥ 0.25hd and DR > 0.5, 3) the opposite bank is endangered by erosion due to strong upward motion along this bank, 4) additional shear layer develops on the outer side of the distorted umax-core and 5) the presence of bed-step favours bed-load transport both in and far downstream of the confluence. PB - CRC Press, Taylor & Francis Group C3 - River Flow 2014, Proceedings of the International Conference on Fluvial Hydraulics, Lausanne, Switzerland, 3-5 September 2014 T1 - Effect of bed elevation discordance in the main river on the confluence hydrodynamics in 90o straight-channels’ confluences EP - 1005 SP - 997 DO - 10.1201/b17133 ER -
@conference{ author = "Đorđević, Dejana", year = "2014", abstract = "A role of the difference in bed elevations in the main-river (ΔzMR) at its entrance to a 90º straight-channels' confluence is studied numerically using a 3D finite-volume model. Three characteristic hydrological scenarios with DR = {0.250, 0.583, 0.750} are analysed in four confluence layouts having ΔzMR / hd [0.0, 0.50] (where hd stands for the flow depth in the deeper canal at the confluence). It is found that: 1) a portion of the tribu-tary flow in the bottom layers is entrained by the bed-step, 2) the w- velocity has the same order of magnitude as Vxy for ΔzMR ≥ 0.25hd and DR > 0.5, 3) the opposite bank is endangered by erosion due to strong upward motion along this bank, 4) additional shear layer develops on the outer side of the distorted umax-core and 5) the presence of bed-step favours bed-load transport both in and far downstream of the confluence.", publisher = "CRC Press, Taylor & Francis Group", journal = "River Flow 2014, Proceedings of the International Conference on Fluvial Hydraulics, Lausanne, Switzerland, 3-5 September 2014", title = "Effect of bed elevation discordance in the main river on the confluence hydrodynamics in 90o straight-channels’ confluences", pages = "1005-997", doi = "10.1201/b17133" }
Đorđević, D.. (2014). Effect of bed elevation discordance in the main river on the confluence hydrodynamics in 90o straight-channels’ confluences. in River Flow 2014, Proceedings of the International Conference on Fluvial Hydraulics, Lausanne, Switzerland, 3-5 September 2014 CRC Press, Taylor & Francis Group., 997-1005. https://doi.org/10.1201/b17133
Đorđević D. Effect of bed elevation discordance in the main river on the confluence hydrodynamics in 90o straight-channels’ confluences. in River Flow 2014, Proceedings of the International Conference on Fluvial Hydraulics, Lausanne, Switzerland, 3-5 September 2014. 2014;:997-1005. doi:10.1201/b17133 .
Đorđević, Dejana, "Effect of bed elevation discordance in the main river on the confluence hydrodynamics in 90o straight-channels’ confluences" in River Flow 2014, Proceedings of the International Conference on Fluvial Hydraulics, Lausanne, Switzerland, 3-5 September 2014 (2014):997-1005, https://doi.org/10.1201/b17133 . .